This research is an inquiry into the effects of early visual experience on perceptual development. Its major objective is to provide a fine-grained analysis of the kinds of visual stimulation that facilitate the young infant's discriminative competence. The experimental design involves (1) the exposure of different groups of infants to two contrasting visual stimuli under a variety of specific perceptual training conditions and (2) the subsequent assessment of their capacity to detect these same stimuli in new contexts. The training conditions, which manipulate functional and perceptual aspects of the visual experience, vary in terms of (a) whether the stimuli have predictive validity or not (i.e., whether they "signal" different or identical consequences) and (b) whether the infant is active or passive in the situation (i.e., whether he must behave to produce the consequences or not). The findings should advance our understanding of the mechanisms which govern early perceptual learning and, as such, should provide a basis for the application of remedial and educational programs to infants.